Electric signaling



De. 16, 1930. L, COHEN 1,785,297

ELECTRIC S IGNALING Filed Nov. 17, 1927 5 Sheets-Sheet l Louis Cohen, W/TNEssEs:- I K Dec. 16, 1930. L. COHEN ELECTRIC SIGNALING Filed Nov. 17, 1927 3 Sheets-Sheet 2 l Louis Hohen,

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De. 16, 1930. COHEN ELECTRIC SIGNALING 3 sheets-sheer 3 Filed NDV. 17, 1927 W/r/vsss u I v f tiiiiiiig, Circuitg; zt'repr hals;

mffoiseleetive t ie A clesli'ecl s Cre uit.

, more' iomplidatec clistributed indiietaiiee nel caloeicity5` on which stationary .Waves gare, estaxlnllsheda jtlie eleetrical length offthe eenliietoigbeing'ad; jtisited to c0riespeicl teen ddd-multiple of t' theiwda21-p infs ofthe, 'staiimayi waves-thus establishing eleetrieal leaksinjtlie form Lof TON @15313 ,T

ial"

. givingaijhiglipotentigtl at fevpenehd O r'the t arefeoiiileetedet npdalpintsfthat s es tablishfr'nelitbf th'efstaitiiian fit1 staii'ctf 'i Therefis 9110 inherent limitation iin L- ,sections j and Ferie; leak 'if aV lesser `sdegiiee of 'building up@ high potentiel Vbeeausieo'fth'e reflection of the Waves backand forth Vonthel Wave C Qiidiietorttheefleeteflwave being 1n nist; rbzinees,y The .reasmjforflt lsv/inherentl i LO than thesi'gnalfor whiohthe Wave'conductor.

"S proper"adjustment,v impressed "o rithe.vr l-Wave ycond.uotc r willy be luy-passedibyth'eleakslY igure T-de fan farrangerhentl f! `metallicreturn :isi-employed fand yva'yejcon ductor' cou'pledito ":angantfenna 7 LeEigni-e .8 'isia-"diagrarnrniatio arrangement Lin :whichij the; leaks?4 'areshown symbolically' to'fdesignateany. type' of anlmf; pedance Y i f embodiments of' lthe invention; and fforrn fa Derfel .thsspelatwnend 1.11

Eigure l isa diagrammatic View of a transf. j

the:

r-Eg'uirefis 'an embodi-Inentloffthe nyentionI in whichfaffdohlewave eonldu'cto rantenna is): shown. 1'1' drawing` of an ligurfe' Q is la? detail diaWngshOWig l'noe-fV chanical arrangement for-the .simultaneous @movement ofafll the Inetalli lates associated- Y.' with theiditferent: sections .zgductonrgr f Figure. isias'ectionaltiere.ofthewave J .conductor and associated flatI metal plate. 5- Figure 11 is another sectional-View Vshow-' filing la metali conductor surroundinglhalf them f i Inl-'all ojtheabovediagrammatic views.v

' corresponding parts are'zindicated h yfthefy same reference characters. V

f Figure -1 :is intended to. iuustmbreadiy the"fundamental"principle.of the invention.

' v A-highfrequency energy source 1f isV connect- V 1 ed'to ground'Qandlterminalfof'the'seetional v @Ofwave conductor- 455 and 6. I-Thepointsand 8,- are separately connected through variableY Aresistanees.Qiand 10 to1gronnd 2; Each sec-fVV fti'on'otthe Wave conductorfis -providedewith 1- 1;; a. 'metal platellwhich is connected to ground 1 l'. 2ft1itoiighthe lead 30.11- The distributed in-.f

1s"the .frequencyY of' the: impressed inthe system..V nyelectriealimnulse, 'other-ifdlictanee `section or (i, yor the"v v oltnge`, L and v`C are the inductance yandea- .i

tisedgfjthatfis, it the" indu'o'tance nd }"c'apaei ty perf. unit length .are thesame Yfollows hate-.impulses are' .1m-

f ,rrowtherlim lsesarefso` tiiried that; alternating impulses for 1the vl-ini-pulse s tvQ travlfthe length' of. theV line and baoljftheelecti offsuccessive iin-` nence'fc'onditiomthat "isgQ-the condition Afor, lonildingaip:ahighfvoltage due to reflection,

is secured When the following relation is obtained;

.eleetroniotiye fiorc'eV isjtlie veio'eityolfpropf agationfandl is the'length'of vthe line.v If

We designatefthe inductanceand.capacity per unit lengtliioflineby-L.andG, thevelocity 1sr theglength of section t or 5, and

'yaZijbthi'itquatiqns" 1j aid 2 are simu.

nr at tinie'finterals eqn'al'tol thatV required jef-@n altfiiating electmmotive l `Also;y-since inall casesofvvavelintuition, the f-Wave velocity V is connected With-l the `Wave given bythe formulas-,

Westf? A; d

length r,\g and the r'equeneyfinithejrelation realize' the condition' `spoken of the line Ymustlhe 'one quarter Wavelength nient maybe effected in a Short distanoe of T.

invention by lmaking the vv'aye @Ondulator in n: the orin of-a `solenoidal coil wound Withvery fine-'Wire and makingthe distributed capacity effective buildingpup iai highl'fvoltagef through line 1es'o11anoe5-4 proyidedg@of-oourse,

the resistance-- losses ofthe conductor Aare not-f -f-toogreat. V' In the a-rra'nz'ge'rnent 4showninfthis ligure,` Y `that is Figure 1Q andfalsodsubsequent lfigures, Ii inaltefuse of'a Waveicondilctor oapablefnof fadjustlnent for the development oivejrn1a-rl`A ter Wave lengths for` any" frequency ofjim which thissysteinisdesigned In thislfigur,

' sectionslland 5 areadjusted'or ahalfvvzwe"l length each and section 6 is'adj'stedor a quarte'n Wavelength; 'In'[thisf cihse5Sl nodal f points areestalolished` atf fandfj8f thatis", j

l? oint-s ofsnhstantiallly ZeropotentiaL/jand neotedfat'thesepoints? f Y. i Y s Y In theicase,I therefore,u or anffalternating ,y eleotrornotive force`ofaafrequenoyfforjwhiohf Y this f system isV adj ilsted,l ahighjpotentialf is established at the extreme open end-1`2fdue methodoffersl a; mea-ns orseonring a higl'rav voltage at the Vpoint, l2 whichinay'lbentis! lized in many Ways particularly in the1=rec"ep j- A tion: of radiosignals as `desorfdoedinConnec-^l established mathematically Yand 7 5andi@"arene-longer nodal points, that is,

fzerogpotential points, and hence'whatever en e1-gy. flovvs on the'oonductor, rnostfofit is by. 7b] Q `passedtowground'throughithevcircuits 7, 9,y f

f .f Zand 85,10; 9andflittle ifanyenergy reaches'Vv .y fore provides ya ldonblemeans 1 for securing selectivity, :discriminating with lgreatfv sharp- V nessin favorofjoneparti `Vis-fnsedf, each section' offhoth wave "Conductors .resonance effect is of Courseabsent, and'in ad- 1 dition,andjthislsfvery important, the pointsA :Vfvvhi'chga-returnvvaveAcon'ductorly5f, andi Y Y. 1s separatelyassociated withanlndependent Y grounded "nietal Vplateto effect af'variation of theeapacity 4(1f-each section.,v For the particii- Y' ar frequency '.fo'r which this systern-` `is ad?V potential is established loetvveen 'vention landitsapplication for? the receptionf ground 2 through the i-ndiietaneelis,coupled through theitran'sfonrner 25.#Seotions rand'f" i l lngithe'-separatio'n distanoes-` of the metal4 platesill from theseotions ofthe Wave Condc'tor'togsatsfy for `the y frequency ofg'the re# and sectionrisvadjnsted tol satisfy theconplates? Either arrangement may loe made tol Y serve the purpose. Y

ceived'signalfthe condition givenVbyf-Equationf s100?. dition' give'nrloyEquation 2,! 4It preierable` 4' toA have-sections, ,4jandy identical in everyre-f A Y spent,V and-:section o'offl thefsamefforin'andj i, *stru@ture hilt only! half "the length ofY either ,4; f for 5,.and`in thatfoase, lthesame'separation of .-1 all 'thefmetal platesllfwill atleet Vall of the sec: .4 tions; infthe samef:way,-and `hencea siinulta@y ineous Vadjustmentrcould' be-=eifeeted;1 V'lhe L v.j metalplates 1l may' beroonneotedfrneohani- Y Gally A131idea dj nstmentefeote'd by :onefmove i 1'0' n l in ent lltfinay'f'alsojbe arranged'to'keepthe Jnetalplatesl'l fixed"andthe:Waveconductor.y 4,5 and inoved vvjith lfresp'eetkto fthe.rnet'fal 'fof tliewave eeondut'or `are adjnstedby vary; A d v 'lished on sectionsfliand. 5 andgaquarterf'vvave length'onseetionj 6 with nodal points atfZ, 'and 8. Anv aidjnstinentis'also to be niadeof the resistances and ,10. For bestfresultsthey f vaines ofthe resistanees 9.and lOmiist bear a relation toythe ratio of the inductanc'e tothe lCapacityo'f the Wave;

also be determinedlexperimentallyi} When the: Vah

eondnjetor' developing fa high y voltageigati the Conductor which I-jhave L what een) ove'v 'conditions are??tnllilled.V stationary-waves areestablished onythefvvave extreme open-fiend y12 Which is impressed: on

the grid ofthethree'eleetrode'vacunm tube In either case halfwaveflengths are estabf "detector 20. An v arnplifierlV may be'fadded. through the transformer connection 19in theV `usual Way. For signals ofdilferent frequen- V cies from the Vfrequency forwhichthissysteni-f' isV an adjustment. thereais no` building-@up of high voltage at the'endlof the Wayeconductor because of line resonance asiinthecase ofthe i frequencyffor` Whichpthis system is ingadjust- '.Inent, and what isleveninore important,- the points V7 and V8 are, no longer `.Zero potential points, and hence any. current flowing: in theV v conductor is vby-p'assed to ground throughthe Aresistance leaks 9.and l0 and therefore, very little'lindsits Way tothe terminal 12..; j;

' .fl-115,1 r fBy this"arrangementtherefore, aJsharp. discrimination is secured in favorof oneparticu- '.lar frequency, that is, high selectivity.

4yThisfsystem is also Very effective in preiventing any'transient disturbances,V suchv as "staticand-others which .may act von the'anten` nato lind its Way to 'the detector. Any elec-` Y tric'l impulse impressed fon thef'wave ccnduc.

'ftomust traverse' the 'Wave conductor vbefore' and a corresponding'. addition of.. thefres'istance` leaks toground.

- Figure a is .a .modifieraam- Y i1; whahaha' Wave conductor is' connected tothe upperVV point oftheloadinginductancel of the antenna 15 and a -commongroundedterminal 21 is-used, Whichrnay'b'e only a WireconnecfV tionn Thetwo terminals'22 and 23 arecon-V nected to grid'and filament ofL a detector or :amplifier tube. 24 'in the usual' Way. L

'i Since thissysteinpossesses a high degree yof I l selectivity, there is: no need Vvto employ any p tuning in they amplifierand a:V resistance :.45

coupled type amplifierrnay .be usedv. j: y A

l-Figure' shoWsa'I embodimentrof the`inyention Yinwhic'h a continuoustwayeff convductor 26 is used and ofsuiicientlength to insurethe development of at least live quarter wavelengths, and resistance leaks 9ja`ndrl0v, connected atvhalf Wavelength intervalsfat;` the'points and 8Which.arenodalpoints.` A"

` grounded 'metallic-returnl is used andthe -systeini's coupled tothe' antenna.

' feo :for turning;V the transformer coil Y embodiment of the. invention'is shown in 'Fig'.{' 1n which a ldouble Wave con- Y 'The modification shownV in Fig; 6 consists.,V Y i l j signal frequency; also :providing resistance n f leaks connected at'tl'eJunctionwpointsof ad-' inf the addition of the Vvariable" condenser 2S 'ductor syst'eind, 6 Vand 4J, 5,",'61is coupled to "anant'enna and associatedwith afdetector Y The embodiment ofthe invention shown in fandfamplifier for the-'reception vof radio sig- 'nals' corresponding to ftheyarrangementdescribed Vin Vconnection with Fig; e2..

FigureJS-differs Vonly from the arrangnnenty shownk in Fig. 4 in v'that theV resistance leaksV 9 and. 10 arereplaced'by impedances :Zi and VZ2 which mayjbeintheform of inductances yor*capacities or any :coinbinationvof inductauces and;capacitiesflt'lnay be observed that-'in all of the arrangements shown in the Various figures, ,theresistances 9 and 10 maybe 'replaced byg ilnpedances, that is, -any combination I of inductances and capacities,

`thoughit is preferable to use resistances. :Also lin all ofthe-gures the plates l1 may l be in' bentforrn to enclose part or most of the Vcoil,1therel;\y lincreasing the capacities of the 'coils to'V ground. A150 Variable` condens- ,tennal an'dfcoupling coils in all ofthe figures.

f Figure 9 is a detailed View showing,V an

arrangement .fforA theI simultaneous adjust-V me'ntlof they 'separation distances of' the grounded metal `pla't'e'sfll from the-.sections 4 5 and 6 ofthe Wavecon'ductori The nietal plates ll) are all connected-to asupport 32 Y which is movable through the sc r'ew, motion Bil [the support 342.. f v sectional View ofthe Wavel f5 ofi the: vrod BfWhich" connected to FigurejlO ifa v A u u conductor 'y and fflat y'i'.netal' plate in'` proximity VFigure ,ll'is a4 YSAe CtiOI'lallvieW ofthe Waye conductorand a bent metal conductor to enclose part Vfofthe coil' ofthe Wave conductor thereby increasing the 'distributed capacity of the .coilto the ground. Y

Without-further descr'ption 4it is thought thatnthe featuresV and advantages ofthe inniaylbe reso'rtedzto, lWithout departing from thefspritvofthe invention-.and scope of the ppenddclam's. 1 KVVQ'I'fclairnz'-` selectiyereceptionof. Velectric signals of a Vparticular' ,frequency Whichllconsists ,iii` interposing; Ybetween the the Vdetecting means, a ysectional -Wave conquarter Wave length' corresponding .to said jacent sections v,ofisaidisectional Wave conf-l tric signals.

ers be'fused in connection Withwthe ani I ceY "Vention Will belreadily" apparent'vto those j .u inthe artfand it lWillo'f course -be understood.ethatlchanges in thereform, pro- V,portion and-fininor detailsV of construction yne ductor and associating with *saidV sectional TWayeyconductorineens for vdetecting said elec- 1 or selectiyesignaling which consistsjinY causing `the-* signals `to pass.` Y

the; .fdetCtQrf` establishing Staticnfry waves throughfa .Wave conductor ,before actingrfon f andfcapacityelectrically associatedIviz'iiththev said antenna circuit,the sai'dlwave conductor consisting zoflalong solenoidalcoil-,a ground-i` j ed metal platev in oloseprioximity tof-thesaid y solenoidal coil ,"V the inductance .and `capacity per vunit length, gandjthe lengthv ofthe rWavev conductor being.; adj usted to insure ,the de? Y lengths for the signal desired tojbe vreceived',

- establishing thereby Ia Vstationary Wave i on the said Wave conductor, impedance-leaks meme?" y ductor. i f

Wave f. conductor- :of distributed iinductance velopnient i of. oddfinultiple i oitl quarter Wave Connected to ground at the nodalfpoints of the saidstationary-V. Wave, and detecting means connected to the extreme openend of the saidvvaveconductoi.

Y velopment of odd multiple of quarter WaveV lengths for thevsignal desired to be receive'd,

4. In a'system `for the reception Voi "radio signals comprising anantenna circuit, a Wave conductor of distributed inductance andca-k pacityelectrically uassociated with the saidi` antenna circuit,`the lsaid wave conductor Vconsisting'of a longlsolenoidal coi1,agrounded metal plate in lclose proximity to the said solenodal coil; the inductancel andcapacity per unit length, andthe length of the Wave conductor beingV adjusted to insure the deestablishing therebyr a stationary Wave on the saidyvave` conductor, variable resistance leaks connected vto ground at the nodal points of the said stationary wave, and ,detecting means connected to the kextreme vopeniend.

of the said-Wave` conductor.

5. In a system-for the reception vofradio signals comprising an antennacircuit, a Wave conductor of distributedinductance and cal the said Wave conductor; the inductance and pacity electrically associated With the` said antenna circuit, the said Wave conductor consisting of a long solenoidal coil and having a grounded metal plate in close proximity to thel saidsolenoidal coil,the separation distance between the ysaid grounded metal plate and the said solenoidal coil being adjustableto thereby vary the distributed capacityoi' capacity per unitlength and the length of the Wave conductor being'adjusted to insure the development of an odd multipleV of quarter Y Wave lengths for the signals ,desired to Vbe received, establishing yastationary Wave on the said Wave conductor, impedance leaksV connected to ground at the nodal pointsot Vthe said stationary-Wave and connecting de-l i tecting means to the extreme open end-of tlie said Wave conductor. l, i 6. In a system for -thereception of radio signals comprising an antenna circuit,"a Wave conductor of' distributed inductance on'- the` lsaid'favvave i conductorrand connecting impedance leaks-jat thel :nodali points offithe f' l ysaidstationarytirare ,on ithe,sa id1v\iaveconj i the de velopnientioi' tive quarterfvvave lengthsV i for thesignals l'desired to be received, estab-` y i lijshingfa.stationary Wave on the't'said Wave conductor, impedance leaks connectedto' groundl atl the nodal pointsfofV the said stationair-yivave-andiconnectinggdetecting means i togth'efextemefopen endfofftheL-said -Wavef t' f conductorl,iv

y 7; :lil-fas'ystem-'for-the :reception of radio i signals comprising an antennagcircuit,ari/ave conductor lof 'distributed -inductanceand ca.` s pacity i electrically associatedv yvvithttlie said :antenna circuit, lthe said Wave conductor lconl sistngioiiailong .solenodalcoil, a garou-ndedv lso,

metallic conductor `zpartially surrounding said sole'nodal coil, lthe: separation distancey 'j 1 -between:thel vsaid solenoidal coil-and saidnie l tallic `conductor;:beingadjustable .toi` thereby 195 conductorgtheinductance andcapacity per unit lengthiandithe lengthrofatheiwave. con'.A y

Avary the distributed capacityiotsaid"Wave ductor beingiadj'usted to;insure'thedevelop;1 i

ment` "ois an f odd'A iemultiplei. offquarter .Wave; lengths forthezsignals.V desiredto be received, I establishing a stationaryV Wave on: the said waves-conductor,:impedance leaks connected Vto ground at the 4nodalV points ofthe. said stationary. iiiiave, and" connecting detecting means tothe:extremeopeniend of the said-V -vvaverconductorg I f i 8. Infaasyste'm for the reception of radio 'i signals comprising an antennacircuit, aWave conductor i:ofidistributedinductance and capacity electrically i associated With the 'said antenna circuit, the` said wave j conductor consisting of aflong-fsolenoidali coil, la `:grounded metallic conductor -partially surrounding: said solenoidalf coil," the l `separation distance between the-said solenoidal coil andfsa'id rne-V ioo tallic conductor 'being :'idjustable to thereby vary fthe :distributed .capacity ofu said Wave conductorfthe inductance and `capacity per;-

unit'length` and the length.` vot thel vvavet'con' ductorv ,being-l adj usted toy insure the ydevelopment of an1 odd vmultiple of quarter -Wvavev lengths lforstliersi-gnals desired' tobe received,

establishing a Astationary ivfave on l the said `Wave conductor, impedance leaks' connected to `ground at -tlie nodal fpoints off the vsaidv stationary f-Wave, the eXtreme fopen' end of said Wave conductorV beingfjconnectedfto the grid I of4 a threeeleetrodevacuum tubejamplier;V *Y f i 9.21n11-1afsystem ffor; the reception otradio v signals @comprising :an anteifina,A a sectional wave! conductor electrically?associatedV :withV the .said antenna, thesaid sectional wave con-' r s ductorlfc'ons'istisiigv of .severaljlsectionsfeach section?l except the last one adjusted for ifa E half wave length corresponding .tothe fre- Y quency'ofthe signal received-the' lajst ofsaidVVV sections adjusted to a Vquarter wavelength..v

of the 4signal received; establishing stationary waves. by vthereceived! .signaly on v said sectional `.waveV conductor ywith nodal'poin'ts at'the Junctions of adJacen'tv sections; 'vari- Y,

able resistance leaks v tov ground connected at the nodalpoints, and'ineans for detectingthe'- signals lconnect-ed at the' eXtreme' open gend fl'lof'said sectional waveconductor.

10.4 In a system iorvthe receptionfofradio.'

signalsk comprising an antenna; a" sectional s waveconductor coupled to the said antenna,V the said sectional wave conductor consisting vl of three sections,;. the iirst two sections` being ductor being variabletogeie'ct thereby v a va'hzf ri'ation'linlthej distributedfcapacityo ea'cli g osaidlfsections; each fof sai'dfsections vexcept. f the last being adjusted `for'lialf Wave lengths receivedandithe lastof said; sections being 570 corresponding'ftoxztlieffrequencyY of( the signal adjusted to quarter wave lengths correspond-l ing tol the frequency 'of vthe signal'received",

establishingstationary, waves by the receivedr-- Y signal onsaid sectional wave conductor with nodalpoints at the vjunction's of adgacentsec. tions Y variable :resistance fleak's to ground connected atthe'lnodal points and means for detectingthe .signals connected kat the eX- treme open enclfofthe said sectional.wave conductoimf Y signature.. f Y Y,

identical 'and 'Veachbeing-Jjadjusted 4for half-4 d wave lengths lcorresponding to the' frequency i ofthe signalto be-.receivedand the last secltion being adjusted vto ya quarterwave lengthv fof thefsignal received; `two yariable resist-` n' l anceleaksto groundwconnected'separately'l lat the two Vjunctionpoints'fof thesaid three Y sectional` wave -conductor,- and@lfdetecting'y Vmeans connected to the extreme said sectional waveconductor. 1 11. In a systemfor the reception of radio` open endofA Louis? corina.

signals com risin anfantenna a sectional` wave conductor velectricallyassociatedvwith 1 fthesaid antenna; the said sectionalv wave conductor consistlng of Iseveral sect1ons,1 each.

section' consistin of a'solenoidal coil lhai/i110r b a grounded metal conductor in close proximity to. it,v the separationdistance between said solenoidal coil and said grounded metal con-V i `ductor being variable to eli'ect therebya va- Vriation in the distributed capacity of'each of said sections; each of said sections except the last being, adjusted Vfor half Wave lengths corresponding to the Yfrequency of the signal received and the last of said sections being adjusted toquarter wave length corresponding to the irequency ofthe signal receivedj establishing stationary .waves by the. received signalon said'sectional wave'yconductor with nodal points at the junctionsof adjacent sections; variable resistance leaks toy ground connected at the nodal points and' means for de.

' tecting the signals connected at the extremev riable condenser, the said sectional wave con-k ductor consisting ofvseveralzsections,,each section consisting 'of 'a solenoidal coil having a grounded metalconductor in close proximity v to it, Vthe separationdistance between said Y :solenoi'dal coil and said. grounded metal con- 

